One size fits most. - 25" max cranium size
Flexible, durable, lightweight.

Listing is for helmet ONLY
Has streaming dream color LED functions with hundreds of settings. The electronics run on an included 5v usb rechargeable cell.
Other features include:
A built-in cooling fan - increases airflow and prevents lens fogging.
Internal microphone - 3.5mm jack which can be plugged into an amplifier, console, or wireless receiver.

***Some people occasionally ask me how to determine head size.
If you're concerned about fitting, unsure of your size, and don't have measuring tape: Simply take a strip of paper, wrap it around your head, mark where it meets with a pencil or tape before removing, then just measure that strip laying flat with a normal ruler.
Hope this helps!

ships in 3-5 days

Any questions feel free to ask!